ira99corvette

I need help diagnosing another C5 fuel tank problem on a 99 Vette. Over the years I have had my share of fuel gauge and tank sensor problems known to plague most C5 vetts. I am now experiencing a new problem. When the tank gets below a half of fuel the car stalls like it is out of gas. There is definitely a 1/2 tank of fuel left in the tank. I have now ran out of gas 3 times. I carry 2 gallons with me so I am not stranded. I already tried techron and seafoam but no improvement. Any help would be greatly appreciated.

Thanks

Ira

wrmiles

There is a small jet pump in the RH tank that transfers fuel to the LH tank. Once the level gets below the gravity interconnect, up high, the LH tank should stay at this level as the RH tank empties. After a number of miles, if the PCM senses this isn't happening, it drives the gauge to zero and and throws code P1431. This could be verified by checking tank sender outputs using a voltmeter or a tech 2.

Fuel left when you run out is 5 or 6 gallons, though, so is closer to 1/4-3/8 than 1/2.

Jet pump is not available separately, so repair choice is either replacing complete assemby, including the gas gauge sender or cleaning the old one (internal nozzle is what is likely to be plugged).

ira99corvette

Thanks guys for the information. Does anyone have the procedure for removing the jet syphon pump? Went through some of the threads but couldn't find it. Tks

RLYSLO

You can download the service manuals for free here : http://forums.corvetteforum.com/c5-t...al-on-dvd.html

It should have a procedure in there that you can go through.

PUMP03

Attached is pdf with Fuel Sender Assy Replace for 1999. If you need additional info from the SI, send me a PM

ira99corvette

Thanks

TorchRed2001

I just replaced my jet pump about a month ago for the exact same reason. I did alot of reading on it and it seemed to be alot of work, and i was skeptical about being able to do it without a lift. I was surprised at how easy it was to replace. I drove the front onto a set of ramps and jacked the rear up as high as i could get it safely, removed the right rear tire. From there you have to remove the straps that hold the gas tank up and disconnect the pump on the back side of the tank.

Since the RH tank is full be prepared for alot of fuel to drain. I went out and bought a brand new oil pan with an open top and put it on a jack and lifted it right under the tank, removed the bottom 3 or 4 screws and took a screw driver and gently wedged it between the tank and the pump trim, let the fuel drain into the oil pan and once it started to get full i tilted the oil pan and allowed the fuel to pour out of the spout into a 5 gallon fuel containers for the dirtbikes. I filled it a little of two times (used 3 fuel containers).

Once the tank was dry i rotated it down a little and the pump pulls right out then you can reverse the process and pour your "liquid gold" back in. overall time was about 1.5 hrs, most of which was waiting for the slow draining fuel.

Hope this helps, good luck